An RDoC-based approach to adolescent self-injurious thoughts and behaviors: The interactive role of social affiliation and cardiac arousal

Self-injurious thoughts and behaviors (SITB) increase dramatically across adolescence. Despite the prevalence and severity of these outcomes, remarkably little research has elucidated why adolescence represents a particularly high-risk period for the emergence of SITB. Recent theoretical models have posited that SITB may result from failures in biological stress regulation in the context of social stress. However, there is a lack of data examining these associations during the transition to adolescence, a sensitive period of development that is characterized by changes across socio-affective and psychophysiological domains that may interact to heighten risk for SITB. The present study used a prospective longitudinal design among 147 adolescents. We built on advantages offered by the RDoC framework to test the interaction of experiences of social conflict (i.e., parent and peer conflict) with cardiac arousal (i.e., resting heart rate) to predict adolescent non-suicidal self-injury (NSSI) and suicidal ideation (SI) across one year. Longitudinal analyses revealed that while neither greater peer conflict nor higher cardiac arousal at baseline were associated with SITB outcomes at follow-up, adolescents experiencing the combination of greater peer conflict and higher cardiac arousal at baseline showed significant longitudinal increases in NSSI at follow-up. In addition, there were null effects for family conflict and SI outcomes. Findings indicate that youth with greater peer conflict and heightened arousal during the transition to adolescence may be at increased risk for NSSI. Future research should examine these processes at finer timescales in order to elucidate whether these factors are proximal predictors of within-day SITB.